Remove unused option in server API

pkg/analysis_server/lib/plugin/protocol/generated_protocol.dart

Index: pkg/analysis_server/lib/plugin/protocol/generated_protocol.dart
diff --git a/pkg/analysis_server/lib/plugin/protocol/generated_protocol.dart b/pkg/analysis_server/lib/plugin/protocol/generated_protocol.dart
index f3c2d98a8556fd5558227675900765721c546a7f..14648d40496ea9b573920ca48a1c90d8c1f9c694 100644
--- a/pkg/analysis_server/lib/plugin/protocol/generated_protocol.dart
+++ b/pkg/analysis_server/lib/plugin/protocol/generated_protocol.dart
@@ -1714,6 +1714,8 @@ class AnalysisSetAnalysisRootsParams implements HasToJson {
   }
 
   /**
+   * Deprecated: This field is now ignored by server.
+   *
    * A mapping from source directories to package roots that should override
    * the normal package: URI resolution mechanism.
    *
@@ -1737,6 +1739,8 @@ class AnalysisSetAnalysisRootsParams implements HasToJson {
   Map<String, String> get packageRoots => _packageRoots;
 
   /**
+   * Deprecated: This field is now ignored by server.
+   *
    * A mapping from source directories to package roots that should override
    * the normal package: URI resolution mechanism.
    *